Add latency measurement system

cc/gl_renderer.h

Index: cc/gl_renderer.h
diff --git a/cc/gl_renderer.h b/cc/gl_renderer.h
index 4cfdfc06a9d4fc7e80ae366d86cba5cbef2fa6b3..4116d9558d641e6f5a11234ff63a03f26515762a 100644
--- a/cc/gl_renderer.h
+++ b/cc/gl_renderer.h
@@ -36,7 +36,8 @@ class ScopedEnsureFramebufferAllocation;
 class CC_EXPORT GLRenderer : public DirectRenderer,
                              public NON_EXPORTED_BASE(WebKit::WebGraphicsContext3D::WebGraphicsSwapBuffersCompleteCallbackCHROMIUM),
                              public NON_EXPORTED_BASE(WebKit::WebGraphicsContext3D::WebGraphicsMemoryAllocationChangedCallbackCHROMIUM),
-                             public NON_EXPORTED_BASE(WebKit::WebGraphicsContext3D::WebGraphicsContextLostCallback) {
+                             public NON_EXPORTED_BASE(WebKit::WebGraphicsContext3D::WebGraphicsContextLostCallback),
+                             public NON_EXPORTED_BASE(WebKit::WebGraphicsContext3D::WebGraphicsLatencyInfoCallbackCHROMIUM){

[jamesr, 2013/01/02 23:23:39]

Why do these come back through a WebGraphicsContext3D interface?  They don't
really have anything to do with a context unless it's a view context, and in
that case they seem more logically part of the surface.

 public:
     static scoped_ptr<GLRenderer> create(RendererClient*, ResourceProvider*);
 
@@ -61,6 +62,8 @@ public:
 
     virtual void setVisible(bool) OVERRIDE;
 
+    virtual void setLatencyInfo(const WebKit::WebLatencyInfoImpl& latency_info) OVERRIDE;
+
     virtual void sendManagedMemoryStats(size_t bytesVisible, size_t bytesVisibleAndNearby, size_t bytesAllocated) OVERRIDE;
 
 protected:
@@ -137,6 +140,8 @@ private:
     // WebGraphicsContext3D::WebGraphicsContextLostCallback implementation.
     virtual void onContextLost() OVERRIDE;
 
+    virtual void onReceivedLatencyInfo(const WebKit::WebLatencyInfo& latency_info) OVERRIDE;
+
     RendererCapabilities m_capabilities;
 
     unsigned m_offscreenFramebufferId;